Devices and methods for left atrial appendage closure

ABSTRACT

Described here are closure devices and methods for ligating tissue, such as the left atrial appendage. Generally, the closure devices include an elongate body, a snare loop assembly comprising a snare and a suture loop, and a shuttle connected to the snare and releasably coupled to the elongate body and retractable therein. In some variations, the shuttle may be configured to fit into the lumen. In other variations, a handle may be attached to the elongate body, and the handle may comprise a track and a snare control coupled to the track. The handle may be configured to release the shuttle from the elongate body and allow movement of the snare control along the track to retract the snare loop and the shuttle into a lumen of the elongate body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/375,660, filed Apr. 4, 2019, which is a continuation of U.S. patentapplication Ser. No. 15,442,216, filed Feb. 24, 2017 (now U.S. Pat. No.10,292,710), which claims priority to U.S. Provisional Application No.62/300,608, filed Feb. 26, 2016 and titled “DEVICES AND METHODS FOR LEFTATRIAL APPENDAGE CLOSURE,” each of which is hereby incorporated byreference in its entirety.

FIELD

The innovations disclosed herein relate generally to devices and methodsfor ligating tissue, such as the left atrial appendage, usingsurgically, minimally invasive, or intravascular approaches.

BACKGROUND

Atrial fibrillation is a common problem that afflicts millions ofpatients. Atrial fibrillation often results in the formation of athrombus, or clot, in the appendage of the left atrium. This presents aproblem, inasmuch as the thrombus can dislodge and embolize to distantorgans, which may result in adverse events such as a stroke. For thisreason, most patients with atrial fibrillation are treated with one ormore blood thinners to help prevent the formation of a thrombus. Bloodthinners, however, can present health risks of their own, especially inthe elderly. These risks, such as bleeding, often require a user to makesignificant lifestyle changes.

Several methods have been developed to address the potential problem ofthrombus formation in the left atrial appendage. One such methodincludes suturing the left atrial appendage along the base or ostialneck where it joins the atrial chamber. In this way, blood flow into theatrial appendage is cut off, eliminating the risk of thrombus formationtherein. Other methods have also been investigated. These methodsinclude stapling the base of the appendage and filling the appendagewith a space-occupying or occluding member. Stapling is not preferredgiven the fragility of the appendage and its tendency to rupture,whereas occlusion devices may not effectively prevent all blood flowinto the appendage.

Most of these procedures are typically performed through open-heartsurgery; however, some may also be performed using minimally invasivetechniques. Open-heart surgery may limit the availability of theseprocedures to those who are at particularly high risk, or who areotherwise undergoing an open-heart procedure. In addition, open-heartsurgery requires general anesthesia and has a number of well-knownrisks, which may make it less desirable for some. Therefore, additionaldevices and methods for closing the left atrial appendage usingminimally invasive, intravascular, or a combination of these techniqueswould be desirable in order to avoid the need for opening the chest.

However, at times, the closure of the left atrial appendage is aconcomitant procedure during other cardiac procedures, and performingthe closure during an open-heart procedure may provide benefits incomparison to a minimally invasive procedure. For example, performingthe closure during an open-heart procedure may make it easier forinstruments to access the heart and may allow for better control ormaneuverability of those instruments. Additionally, using an open-heartapproach may provide a better view of the heart and the surroundingtissue during the procedure. Thus, additional devices for use in opensurgical procedures are desirable, especially when those devices offeradditional advantages over standard devices.

BRIEF SUMMARY

Described here are devices, systems, and methods for closing the leftatrial appendage. In general, the devices described here for closing atarget tissue comprise an elongate body comprising a lumen therethrough.A snare loop assembly may be provided and may comprise a snare and asuture loop releasably coupled to the snare. The snare loop assembly mayextend at least partially from the elongate body. A shuttle may beconnected to a distal portion of the snare and releasably coupled to theelongate body. The shuttle may comprise a configuration to fit into thelumen.

In some variations, the elongate body may comprise an approximatelyL-shaped recess in a side wall of the elongate body. The distal portionof the snare may be positioned in the recess when the shuttle is coupledto the elongate body.

In some instances, the device may comprise a lock wire configured toreleasably couple the shuttle to the elongate body. The shuttle maycomprise a snare lumen and a proximal portion of the snare lumen maycomprise an offset obround.

In some variations, a distal portion of the elongate body may comprise acorner chamfer. A tip may be coupled to the distal portion of theelongate body. The tip may comprise a tip lumen and a proximal portionof the tip may comprise a tip chamfer. The tip chamfer may be 30 degreesand offset from the tip lumen.

The device may include additional features. The elongate body maycomprise a shuttle recess and the shuttle may be disposed within theshuttle recess when the shuttle is coupled to the elongate body. In somevariations, the device may comprise a first configuration in which theshuttle is fixedly coupled to the elongate body and a secondconfiguration in which the shuttle is positioned within the lumen. Insome instances, the shuttle may have a maximum dimension that is lessthan a diameter of the lumen. A diameter of the lumen of the elongatebody may be equal to or less than about 1.60 mm.

In some instances, the devices described here may comprise an elongatebody, a snare loop assembly, a shuttle, and a handle. The snare loopassembly may comprise a snare and a suture loop releasably coupled tothe snare. The snare loop assembly may extend at least partially fromthe elongate body. The shuttle may be releasably coupled to the elongatebody and may be connected to a distal portion of the snare. The handlemay be attached to the elongate body. The handle may comprise a track, asnare control coupled to the track, and a release assembly housed withinthe handle. The snare control may comprise a limiter configured to limitmovement of the snare control along a proximal portion of the track, andthe release assembly may be configured to release the shuttle from theelongate body and disengage the limiter to allow movement of the snarecontrol along the proximal portion of the track.

In some variations, the device may comprise a suture control fortightening the suture loop. The suture control may comprise a proximalportion configured to engage the release assembly through an opening inthe handle and disengage the limiter from the release assembly. Therelease assembly may comprise a flexible latch configured to limitmovement of the release assembly after engagement of the suture controlto the release assembly. The limiter may extend along a length of thetrack and/or a lock wire may be configured to releasably couple theshuttle to the elongate body.

In some variations, the devices described here may comprise an elongatebody, a snare loop assembly, a shuttle, and a handle comprising a lockconfigured to limit movement of the snare control along the track. Thesnare loop assembly may comprise a snare and a suture loop releasablycoupled to the snare and the snare loop assembly may extend at leastpartially from the elongate body. The shuttle may be releasably coupledto the elongate body and may be connected to a distal portion of thesnare. The handle may be attached to the elongate body and mayadditionally comprise a track, a snare control coupled to the track, anda release assembly configured to release the shuttle from the elongatebody and allow movement of the snare control along the track.

In some of these variations, the devices may further comprise a suturecontrol configured to tighten the suture loop. The suture control maycomprise a proximal portion configured to engage the release assemblythrough an opening in the handle and disengage the lock from the releaseassembly. In some variations, the lock may comprise a stopper extendingalong a length of the track. The lock may further comprise a lockengagement portion comprising an opening and the opening may bereleasably coupled to the release assembly. In some variations, therelease engagement portion may extend from a bottom surface of thestopper. The release assembly may comprise a release engagement portionand the lock engagement portion may be releasably coupled to the releaseengagement portion. In some variations, the release engagement portionmay comprise a base and a protrusion, and the protrusion may beconfigured to fit within the opening of the lock to releasably couplethe lock engagement portion and the release engagement portion. In someinstances, the lock may further comprise an end plate. Additionally, insome variations, the device may comprise a lock wire configured toreleasably couple the shuttle to the elongate body.

Also described here are methods of closing a target tissue. In general,the methods may comprise advancing a device towards the target tissue.The device may comprise an elongate body, a snare loop assemblycomprising a snare and a suture loop, and a shuttle connected to thesnare and releasably coupled to the elongate body. The snare loopassembly may be closed around the target tissue. The suture loop may bereleased from the snare loop assembly. The shuttle may be released fromthe elongate body. The shuttle may be retracted into a lumen of theelongate body. The suture loop may be tightened around the targettissue. Methods may also comprise withdrawing the device from the body.

In one variation, shuttle retraction may be performed prior totightening the suture loop. In some instances, the method may furthercomprise opening the closed snare loop assembly. Tightening of thesuture loop may be performed prior to releasing the shuttle from theelongate body. Tightening of the suture loop may be performed afteropening the closed snare loop assembly. In some variations, opening theclosed snare loop assembly may further comprise bending the distal endportion of the snare freely away from the elongate body. In somevariations, a maximum shuttle diameter may be less than a diameter ofthe lumen of the elongate body. In some instances, the device mayfurther comprise a handle attached to the elongate body and the handlemay comprise a track, a snare control coupled to the track, and a lockconfigured to limit movement of the snare control along the track. Thehandle may further comprise a release assembly configured to release theshuttle from the elongate body and allow movement of the snare controlalong the track. In some of these instances, the track may comprise afirst portion and a second portion, and the lock may limit movement ofthe snare control along the second portion of the track.

The methods may include additional variations. In some variations, thesuture loop may be tightened via a suture control. In some of thesevariations, the device may further comprise a handle coupled to theelongate body and retracting the shuttle may further comprise insertinga portion of the suture control through an opening in the handle,engaging a release assembly with the inserted portion of the suturecontrol, and disengaging a lock from the release assembly. In some ofthese variations, the handle may comprise a snare control and a trackwith a first portion and a second portion, and retracting the shuttlemay further comprise removing the lock from a second portion of thetrack and moving the snare control along the second portion of thetrack.

In further variations of the methods, the snare control may comprise alimiter configured to limit movement of the snare control along thetrack. A release assembly may be configured to release the shuttle fromthe elongate body and allow movement of the snare control along thetrack. The track may comprise a first portion and a second portion, andthe limiter may be a lock configured to limit movement of the snarecontrol along the second portion of the track.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a cross-sectional representation of a heart showingvarious anatomical structures.

FIG. 2 is a perspective view of an illustrative closure device that maybe used to close the left atrial appendage.

FIG. 3A is a view of a distal end of an illustrative variation of aclosure device having a snare loop assembly. FIGS. 3B-3F are side viewsof the closure device shown in FIG. 3A.

FIG. 4 is an exploded perspective view of a variation of a closuredevice.

FIGS. 5A and 5B are perspective views of a variation of a closure devicehaving a retractable snare. FIG. 5C is a top view of the closure deviceshown in FIG. 5A.

FIG. 6A is a side view of a variation of an elongate body and tip of aclosure device. FIG. 6B is a perspective view of the elongate body andtip shown in FIG. 6A.

FIGS. 7A and 7B are cross-sectional views of a variation of an elongatebody and tip of a closure device.

FIG. 8 is a perspective view of a proximal end of a tip of a closuredevice.

FIGS. 9A and 9B are perspective views of a variation of a shuttle for aretractable snare.

FIG. 10 is a sectional view of a variation of a shuttle in a lumen of atip of a closure device.

FIGS. 11A-11B and 11D-11E are perspective views of an illustrativevariation of a handle assembly for use with the closure devicesdescribed here. FIG. 11C is a top view of the handle assembly shown inFIG. 11B.

FIG. 12 shows a perspective view of a suture control for use with ahandle assembly.

FIGS. 13A-13B are cross-sectional perspective views of a variation of ahandle assembly of a closure device.

FIGS. 14A and 14C are cross-sectional perspective views of anothervariation of a handle assembly of a closure device. FIG. 14B is across-sectional side view of the handle assembly shown in FIG. 14A.

FIG. 15A is a cross-sectional perspective view of yet another variationof a handle assembly of a closure device. FIG. 15B is a cross-sectionalside view of the handle assembly shown in FIG. 15A.

FIG. 16A is a flowchart for one variation of a tissue closing process.FIGS. 16B-16G are perspective views of a snare loop assembly and handleassembly corresponding to FIG. 16A.

FIG. 17A is a flowchart for another variation of a tissue closingprocess. FIGS. 17B-17G are perspective views of a snare loop assemblyand handle assembly corresponding to FIG. 17A.

FIG. 18 is a perspective view of a variation of a closure device havinga partially retractable shuttle.

DETAILED DESCRIPTION

Described here are devices, systems, and methods for closing tissue, forexample, the left atrial appendage. In instances where the heart is therelevant anatomy, it may be helpful to briefly identify and describe therelevant heart anatomy. FIG. 1 is a cross-sectional view of the heart(100). Shown there are the left atrium (102) and the left ventricle(104). In between the left atrium (102) and the left ventricle (104) isthe mitral valve (also known as the bicuspid valve), which is defined bya pair of mitral valve leaflets (106). The leaflets are connected tochordae tendineae (108) that are connected to papillary muscles (110).The papillary muscles join the ventricular wall (112). The left atrialappendage (114) is shown adjacent to, and is formed from, the wall ofthe left atrium (102).

As can be seen, the left atrial appendage (114) lies within theboundaries of the pericardium (116) and is in close proximity to theventricular wall (112). The left atrial appendage typically has atubular shape that approximates a cone, with a slight narrowing or neckin the plane of the orifice where it joins the left atrium (102). Inpatients with atrial fibrillation, the left atrial appendage (114) isthe most common location for thrombosis formation, which, in time, maydislodge and cause a devastating stroke. Because stroke is the primarycomplication of atrial fibrillation, the left atrial appendage isfrequently excluded from the left atrium in those patients undergoingprocedures to treat atrial fibrillation, and is often removed orexcluded at the time of other surgical procedures, such as mitral valvesurgery, to reduce the risk of a future stroke. The devices and systemsdescribed here help ensure proper closure of the left atrial appendageat the neck or base of the left atrial appendage, along the anatomicostial plane. In this way, exclusion of the entire left atrial appendagefrom systemic circulation may be facilitated.

I. Devices

Described here are closure devices and methods for closing tissues usingthese closure devices. Generally, the closure devices comprise anelongate body and a snare loop assembly that may extend at leastpartially from the elongate body to capture and hold tissue. The snareloop assembly typically comprises a closure element, for example, asnare, and a suture loop releasably coupled to the snare. The snare loopassembly may be closed around tissue to temporarily or permanentlyclose, ligate, or otherwise tighten tissue, and the suture loop may betightened and released from the snare to hold or otherwise maintain thetissue in the closed configuration. Either before or after the sutureloop is tightened, the snare loop assembly may be retracted into theelongate body to facilitate the removal of the closure device fromconfined body spaces. The closure device may include one or moremechanisms that prevent premature retraction of the snare loop assembly.

FIG. 2 depicts one illustrative variation of closure device (200) thatmay be used to close the left atrial appendage. Shown there are a snareloop assembly (202), an elongate body (204), and a handle (206). Asnoted above, the handle (206) may be used to control and actuate thesnare loop assembly (202) through the elongate body (204) in order tomove snare loop assembly (202) between a closed configuration, an opendeployed configuration, and a retracted configuration. When in an openconfiguration, the snare loop assembly (202) and elongate body (204) mayform a continuous loop (208) (e.g., such that the snare loop assembly(202) and the elongate body (204) may fully encircle tissue placed inthe loop (208)). When moved from the open configuration to the closedconfiguration, the size of the loop (208) may be reduced as some or allof the snare loop assembly (202) is withdrawn into the elongate body(204). Finally, in the retracted position, the loop (208) (e.g., a snareand a retention member) may be provided entirely within the elongatebody (204). Alternatively, in the retracted position, a substantialportion of the loop (208) may be provided within the elongate body witha small portion of the loop (208) remaining outside of the elongate body(204).

The closure devices described here may be suitable for advancement tothe left atrial appendage using minimally invasive (e.g., through asmall incision above, beneath, or through the rib cage, through anincision in the costal cartilage or the xiphoid, through a port, throughthe vasculature, and the like) and surgical (e.g., median sternotomy,mini sternotomy, thoracotomy, thoracoscopy, and the like) approaches.

FIG. 3A shows a distal section of an illustrative variation of a closuredevice (300) comprising a snare loop assembly (302) and an elongate body(304) having tip (306). As shown there, the snare loop assembly (302)may comprise a snare (308), a suture loop (310), and a retention member(312), and may be disposed relative to the elongate body (304) such thatat least a portion of the snare loop assembly (302) extends from theelongate body (304) (e.g., via tip (306)). The snare loop assembly (302)is shown in FIG. 3A in an open configuration, and the portion of thesnare loop assembly (302) extending out of elongate body (304) may forma loop (314) having an aperture (316) therethrough. The loop (314) andthe corresponding aperture (316) may be defined by one or morecomponents of the snare loop assembly (302) (e.g., the snare) and may besuitable for encircling tissue such as the left atrial appendage.Generally, the snare (308) may be used to open and close the snare loopassembly (302). In some instances, the retention member (312) may beconfigured to releasably couple the suture loop (310) and the snare(308) and may be configured to release the suture loop (310) from thesnare loop assembly (302) upon application of a sufficient force tosuture loop (310).

A snare loop assembly may further comprise a shuttle to allow a distalportion of a snare loop to be released from a tip of the elongate bodyto allow the snare loop to be retracted into a lumen of the tip.Retraction of the snare loop into the tip reduces a profile of thedevice to improve removal of the device from a body. For example,retraction of the snare into the elongate body may prevent the snarefrom catching on and/or damaging tissue when the device is removed fromthe body after the shuttle is released from the tip. The shuttle mayfunction to releasably connect the snare loop to the tip. A user maycontrol the release of the shuttle through the handle. FIG. 5A is aperspective view of a closure device (500) having an elongate body (502)comprising a tip (503), a shuttle (516), and a retractable snarecomprising a proximal portion (512) and a distal portion (514). Theshuttle (516) may be connected to the distal portion (514) of the snareand releasably coupled to the tip (503) of the elongate body (502).While depicted comprising a tip (503), the elongate body (502) need not.In variations in which a tip is not used, the shuttle may be coupled toa side wall of the elongate body (e.g., at a distal portion or end ofthe elongate body).

When the closure devices are advanced through confined body spaces, suchas the pericardial space, advancement or manipulation of the snare loopassembly within or through these tight spaces may result in portions ofthe snare, such as an end of the snare protruding from the elongatebody, to curve and bend to a greater degree than other portions of thesnare. To form a snare loop, the snare may curve as it leaves a tip ofthe elongate body. A curve of the snare may induce a shift or tilt incomponents connected to the snare relative to the elongate body due tofriction of the snare against the tip.

For instance, a conventional shuttle connected to the snare may shift ortilt upward out of a recess of a tip due to the forces generated by acurve of the snare. An uneven interference is thus generated where thecurved portion of the snare contacts a sidewall of the tip.Consequently, frictional forces may create misalignment of the shuttlewith the tip, which may make assembly and operation of the devicedifficult. Additionally, in some instances, bending or manipulation ofthe snare loop assembly within a confined space may create undesirableinterference from tissue that may become pinched between the snare andthe tip. Accordingly, devices described herein may be configured toallow the snare to bend freely without rubbing or abutting against theelongate body, which may reduce interference, misalignment and tissuepinching.

Additionally, a conventional snare loop may be releasable in that adistal portion of the snare loop may be detached from the tip to allowfor easier removal of the snare loop from around the tissue disposedwithin the loop. However, after releasing a distal portion of the snareloop, the portion of the snare that was encircling the tissue and ashuttle remain exposed and external to the elongate body. This exposedportion of the snare and the shuttle may interact with and catch ontoanatomical features or the suture as the closure device is moved awayfrom the target tissue. Accordingly, devices described herein below maybe configured to allow the snare and the shuttle to fully retract intothe elongate body such that no portion of the snare or shuttle remainsexposed. In other variations, the devices described herein may beconfigured to allow almost the entire snare loop (e.g., a majority ofthe snare loop exposed during a procedure, ⅔ of the exposed snare loop,⅚ of the exposed snare loop, and the like) and thus the snare to retractinto the elongate body such that the shuttle and a small portion of thesnare remains outside the elongate body.

In addition to having an elongate body and a snare loop assembly,closure devices described here typically comprise one or more mechanismsfor controlling manipulation and advancement of the elongate body and/orthe snare loop assembly. For example, a handle or other controlmechanism (e.g., a surgical master-slave robotic system) may be used tocontrol and actuate the snare loop assembly through the elongate body.The handle or other control mechanism may change the snare loop assemblybetween a delivery, or “closed,” configuration and a deployed, or“open,” configuration, and vice versa. Additionally, the handle or othercontrol mechanism may move the snare loop assembly into a retractedconfiguration.

Placing the snare loop assembly in a closed configuration may allow fora low-profile advancement of the snare loop assembly to a targetlocation and/or may allow the snare loop assembly to close around atarget tissue. Conversely, placing a snare loop assembly in an openconfiguration may allow the snare loop assembly to be placed around oneor more target tissues and/or may allow the snare loop assembly torelease one or more target tissues previously closed by the snare loopassembly. Accordingly, the devices described herein may further includea handle and/or one or more other control mechanisms to control releaseof the suture loop from the snare loop assembly, as well as snarerelease and retraction. The closure devices may further includemechanisms that prevent an operator from retracting the snare andshuttle prior to releasing the shuttle from the tip.

The closure devices may contain one or more additional features, as willbe described in more detail below. In some variations, a chamfer may beadded to a distal portion of the elongate body that is covered orpartially covered by a tip, which may prevent the tip from cracking dueto tight tolerances. In other variations, a height of the tip may beincreased relative to the elongate body to reduce stress on the tip,increase clearance, and provide leeway for the elongate body to distortwithin the tip. The manufacturability and reliability of the closuredevices are thus improved. These and other features will be described inmore detail below. It should be appreciated that the closure devicesdescribed here may comprise any combination of these features and theother features described and/or incorporated by reference.

The closure devices described here may include any suitable elements orcombinations of elements such as those described in U.S. patentapplication Ser. No. 14/195,797, entitled “Tissue Ligation Devices andMethods Therefor” and filed on Mar. 3, 2014, the contents of which areincorporated by reference herein in its entirety. Individual componentsof the closure devices described here will be described in more detailbelow.

Elongate Body

As mentioned briefly above, the closure devices described here maygenerally comprise an elongate body. The elongate body may connect thedistal end of the snare loop assembly and the handle or actuatingmechanism while still allowing for control of the snare loop assemblythrough the elongate body. Specifically, at least a portion of some ofthe snare loop assembly components may be housed within the elongatebody, and may be connected to the handle through the elongate body. Insome variations, at least a portion of the elongate body may beflexible, which may help facilitate navigation of the elongate bodythrough the body.

The elongate body may generally comprise a tip at the distal endthereof. In some variations, the tip of the elongate body may be formedseparately from the elongate body, and may be attached to the elongatebody during assembly of the device. For example, in some variations, thetip and the elongate body may be attached by a sliding fit and/oradhesive. In other variations the tip portion may be formed integrallywith the elongate body as a unitary device. The tip portion may serve anumber of useful functions for the closure device. In some instances,the tip may be configured to be atraumatic, which may act to reduce therisk of damaging tissue as the proximal end of the elongate body ismoved within the body. In other instances, the tip may allow certainportions of the snare to pass through a lumen of the elongate body whileholding other portions in place relative to elongate body, as will bedescribed in more detail below.

The tip may have the same number of lumens as the elongate body, butneed not. Indeed, in some variations, the tip may divide one or morelumens of the elongate body into two or more sub-lumens. In othervariations, the tip may alter the size or shape of one or more lumens ofthe elongate body.

The elongate body may comprise various sections or portions withdifferent characteristics, for example, different diameters,cross-sectional shapes, stiffnesses, materials, and the like, which mayincrease the steerability and maneuverability of the closure device.

The elongate body may comprise any suitable length, and the length ofthe elongate body may vary depending on the type of procedure beingperformed. The elongate body may be made of any suitable material, forexample, one or more polymers (e.g., polyether block amide,polyethylene, silicone, polyvinyl chloride, latex, polyurethane, PTFE,nylon, and the like). During a minimally invasive procedure, theelongate body may have to travel a further distance through the body toreach a target tissue than when the device is used in a surgicalprocedure. Thus, it may be desirable to use a longer elongate body whenusing the device in a minimally invasive procedure and a shorterelongate body when using the device in a surgical procedure.

Moreover, the elongate body may comprise any suitable cross-sectionalshape, for example, circular, oval, D-shaped, triangular, and the like.In some embodiments, the cross-sectional shape of the elongate body mayvary along its length. In some variations, the elongate body may bedescribed as having multiple portions, each portion corresponding to aspecific cross-sectional shape. For example, the elongate body maycomprise a proximal portion with a first cross-sectional shape (e.g.,circular) and a distal portion with a second cross-sectional shape(e.g., D-shaped). Of course, the elongate body may comprise any suitablenumber of portions, e.g., two, three, or four portions, and the lengthof each portion may be the same as or different from the other portions.

The elongate body may also comprise any suitable outer diameter, and, insome instances, the outer diameter of the elongate body may also varyalong its length. For example, in instances in which the closure deviceis used during a minimally invasive procedure, it may be desirable tolimit the outer diameter of the elongate body such that it may fitthrough 13-French percutaneous tubing.

The elongate body may further comprise one or more transitionsconnecting the portions of the elongate body comprising differentdiameters or different cross-sectional shapes. These transitions mayhave any suitable length.

Lumens

The elongate bodies described here may have any suitable number oflumens. As used herein, “lumen” may refer to any bore or passagewayextending through or partially through a length of the elongate body orother portion of the closure device (e.g., through a handle). It shouldbe appreciated that a lumen need not be entirely enclosed (i.e., thelumen may comprise one or more slots, slits, gaps, or other openingsalong some or all of the length of the lumen). The elongate body maycomprise one, two, three, four, or five or more lumens. Some or all ofthe lumens may extend entirely through the elongate body (i.e., from theproximal end of the elongate body to the distal end of the elongatebody). Other lumens may pass through only a portion of the elongate body(e.g., from one end to an intermediate point along the elongate body, orbetween two intermediate points along the elongate body).

The various components of the snare loop assembly may be housed withinany lumen or lumens of the elongate body. For example, in somevariations, all of the components of the snare loop assembly may behoused in a single lumen. In other variations, different portions of thesnare loop assembly may be at least partially housed in differentlumens. For example, the free end of the suture loop may pass to thehandle through a first lumen, while the free end of the snare may passto the handle through a second lumen. In some variations, there may beexcess suture housed within the elongate body, and this excess suturemay be housed in any suitable lumen. For example, the excess suture maybe held in the same lumen as the free end of the suture loop, in thesame lumen as the free end of the snare, or in an altogether differentlumen.

While the lumens shown herein are depicted in specified locations withinthe elongate body, the lumens may be positioned in any location withinthe elongate body (i.e., their centers may be moved and their locationsshifted); however, it may be desirable to maintain a minimum wallthickness between the lumens to prevent breakthrough. For example, insome variations, it may be necessary to heat the elongate body after itis extruded or otherwise manufactured to attach, insert, or bond withother elements to the closure device. Heating the elongate body maycause the lumens to shift locations or change in size. In someinstances, a portion of the material separating the two lumens may seversuch that the lumens converge or otherwise come together forming onelumen instead of two.

In order to decrease the likelihood of this breakthrough, it may bedesirable to maintain a minimum distance between the lumens duringextrusion and/or heating. Additionally, as described above, in somevariations, a portion of the elongate body may comprise a D-shapedcross-section, which may be created by cutting, shaving, skiving, orotherwise removing a portion of the elongate body. In these variations,maintaining a minimum wall thickness between the lumens may prevent thelumens from shifting during heating and becoming severed when theelongate body is cut to create the D-shape. Accordingly, in somevariations, it may be desirable to maintain at least about a 0.005″(0.127 mm) wall thickness between the lumens.

Additionally, in some variations, the lumens may comprise a lining or acoating designed to reduce the frictional forces between the internalsurface of the lumens and the components housed within them. The smallsize of the lumens, their relative locations, the materials used, andthe precision required to fabricate the elongate body may result inmanufacturing variations (e.g., different frictional characteristicsinside the lumens) between different lots and/or differentmanufacturers. These variations may lead to an inconsistent userexperience and may result in frustration with the closure device and/orimproper usage. For example, if the frictional forces between theinternal surface of the suture lumen and the suture vary, the user maybe required to apply different amounts of force to tighten the sutureeach time the device is used. This may result in over or undertightening of the suture around the tissue. Accordingly, in someembodiments, the suture lumen may comprise a friction-reducing lining orcoating (e.g., a polytetrafluoroethylene (PTFE)). It may be desirable toinclude a friction-reducing lining in any and/or all of the lumens ofthe elongate body, as doing so may result in a more consistent andpredictable user experience.

Tip

In some variations, the tip of the elongate body may be formedseparately from the elongate body and the tip may be coupled to theelongate body by sliding the tip over the distal end of the elongatebody. FIGS. 6A and 6B are side and perspective views of a variation ofan elongate body (604) and a tip (602) of a closure device (600). Inthis variation, the tip (602) and the elongate body (604) are configuredto provide a sliding fit where the elongate body (604) is secured withina cavity (610) of the tip (602). The distal end portion (606) of theelongate body (604) may comprise a corner chamfer (608), which may helpprevent the tip (602) from cracking or becoming damaged by removing acontact point between the distal end portion (606) of the elongate body(604) and the tip (602) where stress may concentrate.

In one particular variation, the outermost diameter of the elongate body(604) may be 0.148 inches±0.002 inches (3.7592 mm±0.0508 mm), the heightof the distal end (606) may be 0.096 inches±0.002 inches (0.24384mm±0.0508 mm), an inside diameter of the tip (602) defining the tipcavity may be 0.148 inches+0.002/−0.001 inches (3.7592 mm+0.0508/−0.0254mm), and an inside height of the tip may be 0.099 inches±0.002 inches(2.5146 mm±0.0508 mm).

In some variations, a gap or clearance may be formed between an externalsurface of the elongate body and an internal surface of the tip (i.e., asurface of the cavity) once the distal end portion of the elongate bodyis placed within the cavity of the tip. The gap or clearance formedbetween the elongate body and the tip may assist in providing aconsistent and reliable fit between the elongate body and the tip, andmay lower stress on the tip by providing more space for the elongatebody to distort within the tip. In some variations, the gap or clearancemay be formed by increasing an inner (and in some variations, an outerdiameter) of the tip, while in other variations, for example those inwhich a D-shaped tip is used, the diameter of the tip may remainconstant while the height of the tip may be increased.

FIGS. 7A and 7B are cross-sectional views of a variation of an elongatebody (704) positioned within a cavity of a tip (702). As shown in FIGS.7A and 7B, the tip (702) and the elongate body (704) may have aclearance (712) between them. The elongate body (704) may comprise afirst lumen (706), a second lumen (708), a third lumen (710), and cornerchamfers (714). The tip (702) and at least a portion of the elongatebody (704) (e.g., a distal portion) may have a D-shaped cross-sectionalshape, each with a height (703, 705). In some variations, the height(703) of the tip (702) may be larger than a height (705) of the distalportion of the elongate body (704) such that the clearance (712) isformed between the tip and the elongate body (e.g., between the flat orlinear bottom surfaces of the tip (702) and the elongate body (704)).The tip may have any suitable height, however, it may be useful to sizeand configure the tip so that it does not interfere with othercomponents that may be used with the closure device during a closureprocedure, for example, a guidewire and/or a guide/delivery cannula. Forexample, in some variations, the height of the tip may be selected suchthat the tip and a guidewire may fit (e.g., stacked) within a lumen of adelivery cannula. Thus, in some variations, the height and thickness ofthe tip combined with the diameter of the guidewire may be less than adiameter of a lumen of a delivery cannula, for example, a 13 Frenchdelivery cannula having a lumen diameter of about 0.174 inches.

For example, in some variations, it may be useful to utilize a tip (702)with an external height in a range of about 0.115 inches (2.921 mm) toabout 0.125 inches (3.175 mm). Additionally, as mentioned above, thediameters/heights of the tip and the distal end of the elongate body maybe selected such that a suitable gap or clearance is created betweenthem, for example, a clearance between about 0.001 inches (0.0254 mm)and about 0.012 inches (0.305 mm). For example, in some variations, theexternal height of the tip may be about 0.120″ (3.048 mm), the internalheight (703) of the tip (702) may be about between about 0.099inches±0.002 inches (2.515 mm±0.0508 mm) and 0.104 inches±0.002 inches(2.642 mm±0.0508 mm), and the height of the distal end of the elongatebody may be between about 0.094 inches (2.388 mm) and about 0.098 inches(2.489 mm). For example, as shown in FIG. 7A, in some variations, theheight (703) of the tip (702) may be about 0.106 inches (2.692 mm),which may provide a clearance (712) height of about 0.012 inches (0.330mm) when the distal end of the elongate body (704) is positioned withinthe tip (702). In other variations, for example, the variation shown inFIG. 7B, the height (703) of the tip (702) may be about 0.104 inches(2.642 mm), which may provide a clearance (712) height of about 0.008inches (0.2032 mm) relative to the elongate body (704). The foregoingare simply examples and any combination of heights of the tip and distalend of the elongate body (e.g., any combination of heights for eachselected from values within the ranges contained above) that result in aclearance between about 0.001 inches (0.0254 mm) and about 0.012 inches(0.305 mm) may be used.

The front surface of the tip may also comprise one or more (e.g., two,three, four, or more) lumens, which may, but need not, correspond to thelumens of the elongate body. The tip lumens may have different diametersand/or cross-sectional shapes than one another. For example, referringto the embodiment depicted in FIGS. 7A and 7B, the tip (702) maycomprise first, second, and third lumens corresponding to the first,second, and third lumens (706, 708, 710) of the elongate body. While allthe lumens are depicted as having a circular cross-sectional shape, thisneed not be the case, and the lumens may have any suitablecross-sectional shape (e.g., oval, square, rectangular, a combinationthereof, and the like). Each lumen may have a different diameter or thesame diameter.

FIG. 8 depicts a perspective view of a proximal end portion of a tip(800) comprising a front surface (808) with a first tip lumen (802)having a corresponding tip chamfer (804) and a second tip lumen (806).In some instances, the tip may scuff or rub against a retention memberwhen a snare assembly is opened and closed. However, there may bedifficulty in simply increasing the diameter of the first lumen of thetip to reduce scuffing due to the space occupied by the retractablesnare and the recess occupied by the shuttle. In these instances, it maybe desirable to add a tip chamfer (804) to the first tip lumen (802) toreduce scuffing when the snare loop assembly is open and closed. The tipchamfer (804) may have any suitable angle, for example, it may be a 30degree chamfer offset from center of the first tip lumen (802) orbetween about 20 degrees and about 60 degrees. In one variation, thediameter of first tip lumen (802) may be approximately 0.063 inches(1.60 mm).

Snare Loop Assembly

As mentioned above, the snare loop assemblies of the closure devicesdescribed here may be used to temporarily close or restrict one or moretarget tissues. Generally, the snare loop assembly comprises a closureelement, e.g., a snare, and a suture loop releasably attached to theclosure element. In some variations, the snare loop assembly maycomprise a retention member at least temporarily connecting the closureelement and the suture loop.

In variations of snare loop assemblies comprising a snare, the snare maybe at least partially moveable to change a snare loop assembly betweenopen, closed, and retracted configurations. Generally, a portion of thesnare may be housed in the elongate body, and another portion of thesnare may extend outside of the distal end of the elongate body to atleast partially define the loop and aperture of the snare loop assembly.

In some variations, one end of the snare is releasably fixed relative toone or more portions of the closure device, while the other end may beadvanced or retracted through the elongate body. Movement of the freeend of the snare may change the amount of the snare loop assembly thatis disposed outside of elongate body, and thus may change the size(e.g., diameter, circumference, area, etc.) of the loop and the aperturedefined thereby. Specifically, advancement of the free end of the snarethrough the elongate body may increase the size of the loop and apertureof the snare loop assembly, while retraction of the free end of thesnare may decrease the size of the loop and aperture of the snare loopassembly. The free end of the snare may be manipulated in any suitablemanner. In some variations, the snare may be attached directly to one ormore portions of the handle. In other variations, a hypotube, rod, orother rigid structure may be attached to the free end of the snare. Thisstructure may in turn be moved by the handle, which may help facilitateadvancement or withdrawal of the snare through the elongate body.

In a retracted configuration, the fixed end of the snare is released andan entirety of the snare and shuttle are retracted into a lumen of theelongate body, as illustrated in, for example, FIGS. 16F and 17F. Theshuttle, which may be coupled to the distal (fixed) end of the snare,may be configured to fit through a lumen in the tip and a lumen of theelongate body (e.g., a first lumen (706) of the elongate body (704) asdepicted in FIGS. 7A-7B, a first tip lumen (802) as depicted in FIG. 8).

The closure elements or snares described here may be made of anysuitable material or combination of materials. For example, in somevariations, the snare may be made from a shape-memory material, such asa shape-memory alloy (e.g., a nickel titanium alloy, etc.), or may bemade from stainless steel, polyester, nylon, polyethylene,polypropylene, combinations thereof, and the like. In variations wherethe snare is made from a shape-memory material, the snare may beconfigured to take on a particular shape or configuration when the snareloop assembly is placed in an open configuration, but may still be atleast partially withdrawn into the elongate body to place the snare loopassembly in a closed configuration. For example, the snare may form agenerally circular, teardrop-shaped, oval or ellipsoid, or triangularloop when the snare loop assembly is placed in an open configuration.

Furthermore, in some variations, the snare loop assembly may be angledrelative to the elongate body. As shown in FIGS. 3A and 3B, the plane ofsnare loop assembly (302) is approximately perpendicular to the distalend of the elongate body (304), however, the plane of the snare loopassembly (302) may be varied over a wide range of angles (a), asdepicted in FIGS. 3B-3F. For example, the angle (a) formed between theplane of the snare loop assembly (302) and the distal end of theelongate body (304), may be between about 5 degrees and about 85 degrees(FIG. 3C), may be about 90 degrees (FIGS. 3A and 3B), may be betweenabout 95 degrees and about 175 degrees (FIG. 3D), may be about 180degrees (FIG. 3E), or may be between about 185 degrees and about 270degrees (FIG. 3F). In some variations, the angle (a) formed between theplane of the snare loop assembly (302) and the distal end of theelongate body (302) may be between about 5 degrees and about 45 degrees.Angling the snare relative to the elongate body may aid the snare incapturing tissue, as angling may better position the snare relative totissue as the closure device is moved in the body. In some variations,the angle (a) may be preset, while in other variations, the angle (a) isadjustable within a predetermined range.

Suture Loop

The snare loop assemblies described here may also comprise a suture loopfor maintaining tissue in a closed manner. Generally, the suture loopmay be releasably attached to the snare, for example, via a retentionmember, as will be described in more detail below. Furthermore, thesuture loop may comprise a suture knot, but need not. This suture knotmay be any suitable knot, including, but not limited to, a slip knot(e.g., a one-way slip knot) or a Meltzer knot. In some variations, atleast a portion of the knot may be held within the tip of the elongatebody. In other variations, the suture knot at least partially extendsfrom the tip of the elongate body or may be positioned outside of thetip and may be temporarily held in fixed relation to the elongate body.When the suture loop comprises a suture knot, the suture loop maycomprise a loop portion, a suture knot, and a tail extending from thesuture knot. The suture tail may be pulled through the suture knot toreduce the diameter of the loop portion.

In variations where the suture loop comprises a slip knot, the suturemay be advanced or withdrawn through the slip knot to change the size ofthe suture loop. In instances where the suture knot is held within oragainst a tip of the elongate body, the suture knot may not move whilethe size of the suture loop is changed. This may help prevent theclosure device from damaging tissue. In some variations, the suture loopmay comprise a unidirectional locking structure. In these variations,the unidirectional locking structure may be any structure capable ofbeing advanced along the suture in one direction but resisting movementin a second direction. In these variations, the locking structure may beadvanced over a portion of the suture loop to help lock a suture knot inplace. For example, in some variations, the unidirectional lockingstructure may comprise a bead or a mechanical structure that is placedat least partially around the suture. In these variations, the bead maycomprise one or more teeth or projections that allow the bead to beadvanced along the suture in one direction, but prevent or resistmovement in the opposite direction. The locking structure may beadvanced via one of the closure devices described here, or it may beadvanced by a separate device after the suture loop has been releasedfrom the closure device.

The suture loop may be made from any suitable material useful in tissueexclusion or closure. For example, it may be made of a biodegradablematerial (e.g., polylactic acid, polyglycolic acid,polylactic-co-glycolic acid, etc.), or it may be made of anon-biodegradable material (e.g., metal, steel, polyester, nylon,propylene, silk, combinations thereof, etc.).

When the suture loop is tightened to close tissue, it may be possiblefor tissue to be pulled into the suture knot of the suture loop. If toomuch tissue is pulled into the suture knot, the suture knot may clog orjam in a way that prevents the suture loop from being further tightened.In some variations the suture loop may comprise one or more pledgets ortube sections to help shield a portion of the suture knot.

Retention Member

When the snare loop assemblies described here comprise a retentionmember releasably coupling a snare and a suture loop, the retentionmember may be any suitable member, such as dual-lumen tubing. In somevariations, one lumen may have a slit, perforation, or other openingalong its length, which may allow the suture to pass therethrough whenit is ready to be deployed. The slit need not extend or be continuousalong the entire length of the retention member. In some variations, theslit may have prongs or arms along its length to help capture and retainthe suture in the retention member. In other variations, the slit may becovered at spaced-apart locations with a biodegradable polymer, whichmay temporarily tack or hold down the suture. Of course, in still othervariations, the retention member does not comprise a slit, and insteadcomprises some other type of retention mechanism, such as the prongs ortacks described just above. In yet other variations, there are no slitsor openings in the retention member, and the suture loop is releasedupon removing or withdrawing the retention member.

Excess-Suture Management

In operation of the closure devices, it may be desirable to be able toopen and close a snare loop assembly without prematurely releasing thesuture loop from the snare assembly. Because the size of the loop of thesnare loop assembly and the aperture defined thereby changes as thesnare loop assembly is opened and closed, it may be necessary for thesize of the suture loop to change in order to accommodate this change inaperture size and to prevent the suture from being prematurely releasedfrom the snare loop assembly. In some variations, opening the snare loopassembly may pull a suture through a slip knot to increase the size ofthe suture loop. This may, however, provide sufficient force to thesuture loop to cause the suture to break or sever.

To help prevent this undesirable outcome, in other variations, thesuture loop may be sized such that the suture loop is as large as orlarger than the size of the aperture defined by the loop of the snareloop assembly when the snare loop assembly is in an open configuration.In this manner, the suture does not translate through the knot while thesuture is loaded on the device and the size of the suture loop does notchange. Thus, when the snare loop assembly is moved to either an open orclosed configuration, the suture loop can assume a similar size withoutneeding to advance additional suture through the suture knot.

Pre-sizing the suture loop to such a size, however, may result in extraslack in the suture loop when the snare is in both the open and closedconfigurations. To help prevent the excess suture from getting entangledwith or caught on anatomical structures, instruments, or otherobstructions, some or all of the slack in the suture loop may be heldinside of the elongate body when the snare loop assembly is openedand/or closed. As such, the closure devices described here may compriseone or more excess-suture management features, which may be used in anysuitable manner. The closure devices described here may comprise anysuitable suture management features, for example, any of those describedin U.S. patent application Ser. No. 12/752,873, entitled “TissueLigation Devices and Controls Therefor” and filed on Apr. 1, 2010, theentire content of which is incorporated by reference herein.

Retractable Snare

As mentioned above, in some variations, the closure devices describedhere may comprise a retractable snare. In some variations, the snare maybe configured to be releasable along its length to separate the snareinto two separate snare portions, as well as configured to beretractable through a lumen of the elongate body. In other variations,the closure device may comprise a snare having an end that is fixedrelative to the elongate body, and the closure device may be furtherconfigured to release the fixed end of the snare and retract thepreviously fixed end of the snare into the elongate body. In somevariations, the closure device may comprise a snare that has a fixeddistal portion that is releasable from a side wall of the elongate body(or a tip thereof). For example, the closure device may comprise a firstconfiguration in which a shuttle coupled to a distal end of the snare isfixedly coupled to the elongate body, and a second configuration inwhich the shuttle and the distal end of the snare are positioned withina lumen of the elongate body. In these variations, the fixed end of thesnare, which may or may not be coupled to a shuttle, may be releasedfrom the closure device in any suitable manner.

FIG. 4 is an exploded perspective view of a variation of a closuredevice. FIG. 4 shows a perspective view of a distal portion of theclosure device (400) comprising a tip (402), a shuttle (420) comprisinga window or lock wire recess (422), and a lock wire (424). As shownthere, the tip (402) may comprise a shuttle recess (408) having a rearsurface (412) and a front surface (414), first and second lumens (404,406), an L-shaped recess (410) extending between the front surface (414)of the shuttle recess (408) and a front surface of the tip (428), and alock wire lumen (418). Also shown there is a track (416) furtherdisposed in the shuttle recess (408). When the shuttle (420) is coupledto the tip (402), the shuttle may be positioned within the shuttlerecess (408) and optionally the track (416). The shuttle (420) may beconnected to a distal portion of the snare (not shown), which may bepositioned in the approximately L-shaped recess (410), as will bedescribed in detail below.

The lock wire (424) may be configured to extend through the tip (402)and the shuttle (420) and into the lock wire lumen (418). Whensufficient force is applied to the lock wire (424) (e.g., at a proximalend thereof), the lock wire (424) may be retracted and the shuttle (420)may be released from the tip (402). In some variations, the lock wire(424) may comprise one or more bends (426) or coils, which may resistmovement relative to the shuttle and/or elongate body. The bend (426) inthe lock wire (424) may be configured to be disposed within the windowor lock wire recess (422) of the shuttle (420) while the shuttle (420)is coupled to the tip (402). The bend (426) in the lock wire (424) mayprevent low levels of force from retracting the lock wire (424) (i.e.,may reduce the risk of premature or inadvertent release) as the bend(426) may contact a side wall of the lock wire recess (422), which maykeep the lock wire from further retracting without sufficient force. Torelease the lock wire (424), the user may apply a proximal force (e.g.,via a control) sufficient to straighten the bend (426).

As mentioned above, the snare may have a fixed distal portion that maybe releasable from a tip attached to the elongate body, or from a sidewall of the elongate body, and retractable through a lumen of theelongate body. FIGS. 5A and 5B are perspective views of a distal portionof a closure device (500) having a retractable snare. FIG. 5C is a topview of the closure device (500) shown in FIG. 5A. As shown in FIG. 5A,the closure device (500) may comprise an elongate body with a tip (503)and a snare loop assembly (501) at least partially extending from thetip (503). The snare loop assembly (501) may comprise a snare comprisinga proximal portion (512) and a distal portion (514), and a suture loop(not shown) releasably coupled to the snare (512, 514), via, forexample, a retention member (not shown). A shuttle (516) may beconnected to the distal portion (514) of the snare and may be releasablycoupled to the tip (503) of the elongate body. For example, the tip(503) may comprise a shuttle recess (509) and an approximately L-shapedrecess (510) in a side wall of thereof. When the shuttle (516) iscoupled to the tip (503), the shuttle (516) may be positioned within theshuttle recess (509) and the distal portion (514) of the snare may bepositioned in the L-shaped recess (510).

As shown in FIG. 5B, the closure device (500) may comprise an elongatebody (502) comprising a tip (503) coupled to a distal portion of theelongate body (502). A snare loop assembly may comprise a snare and asuture loop, although only a proximal portion (512) of the snare and adistal portion (514) of the snare are shown in FIG. 5B. The proximalportion (512) of the snare may extend from a first lumen (504) of thetip (503) to form a loop defining an aperture that may be placed aroundtissue. When a suture loop comprises a suture knot (not shown), thesuture knot and a tail of the suture loop may be positioned in and/orextend through the second lumen (506).

The proximal portion (512) of the snare may extend through the firstlumen (504), where it may be operatively connected to a handle assembly(not shown). The handle assembly may advance and retract a proximal endof the snare (e.g., proximal to the proximal portion shown) to controlthe size (e.g., diameter, circumference) of the aperture formed by snareloop assembly. Since the suture loop (not shown) is coupled to thesnare, movement of the proximal end of the snare may move part of thesuture loop into or out of the first lumen (504). Additionally, invariations in which the suture loop is sized to have an amount of excesssuture, some or all of the excess suture may be held or otherwisemaintained in the first lumen (504) of the tip (503) or within a lumenof the elongate body.

The tip (503) may additionally comprise a lock wire lumen (508) bothdistal and proximal to the shuttle recess (509), and thus the shuttle(516) when the shuttle (516) is positioned within the shuttle recess(509). The lock wire lumen (508) may be configured to secure the shuttle(516) relative to the tip (503) when a lock wire (520) is extendedthrough the tip (503) from the elongate body, positioned through awindow or lock wire recess (518) of the shuttle (516), and through thelock wire lumen (508). The window (518) may also be open into the sideof the tip (503), which may allow a bend of the lock wire (520) toextend at least partially into the window (518) to resist proximalmovement of the lock wire (520) relative to the shuttle (516).

The proximal portion (512) of the snare may be operatively connected toa handle assembly and a distal portion (514) of the snare may beconnected to the shuttle (516). Generally, the shuttle (516) may be astructure configured to couple the distal portion (514) of the snare tothe tip (503) of the closure device. The shuttle (516) may be coupled tothe distal portion (514) of the snare and may be releasably coupled tothe tip (503) of the closure device, and may thus be configured to fixthe distal portion (514) of the snare relative to the tip (503). Whenthe shuttle (516) is coupled to the tip (503), the distal portion (514)of the snare is fixed relative to the tip (503), and a proximal end (andthe proximal portion (512)) of the snare may be advanced or withdrawn(e.g., via a control such as a handle assembly) to open or close thesnare and snare loop assembly.

As shown in FIGS. 5A-5C, the distal portion (514) of the snare may bepositioned in the approximately L-shaped recess (510) when the shuttle(516) is coupled to the tip (503) (e.g., positioned in a shuttle recess(509) of the tip (503)). The approximately L-shaped recess (510) maycomprise a first surface (511) and a second surface (513) that istransverse to the first surface (511). In some variations, the secondsurface (513) may be perpendicular (i.e., at an approximately 90 degreeangle) to the first surface (511), while in other variations, the secondsurface (513) may be angled away from the first surface (511). Forexample, the angle may be any suitable angle that prevents interferenceof the second surface (513) with the distal portion (514) of the snareand does not otherwise interfere with or breakthrough the second lumen(506). For example, the angle between the first and second surfaces(511, 513) may be an obtuse angle, for example, about 100 degrees, about105 degrees, about 110 degrees, between about 90 degrees and about 105degrees, between about 95 degrees and about 110 degrees, or the like. Insome variations, the second surface (513) may form a shelf on which atleast a portion of the distal portion (514) of the snare may restwithout being confined. The L-shaped recess (510) may be configured suchthat the distal portion (514) of the snare positioned in the recess(510) may bend freely away from the tip (503) (e.g., a longitudinal axisof the tip). In this way, the snare loop assembly may be transitionedfrom an open configuration to a closed configuration and vice versawithout being constrained by the surfaces of the recess (510).

Utilizing a recess (510) with first and second surfaces (511, 513) thatare perpendicular or form an obtuse angle relative to one another mayprovide a number of advantages compared with conventional U-shapedrecesses. For example, conventional U-shaped recesses do not allow adistal portion of a snare to bend freely and are thus prone tointerference, misalignment, and tissue pinching. In contrast, as thedistal portion (514) of the snare is able to bend and move away from acentral longitudinal axis of the tip (503) without being constrained bythe surfaces of the recess (510), the distal portion (514) does notencounter interference from the tip (503) or shuttle (516). Thus,frictional forces and/or an obstruction that may otherwise force theshuttle (516) to tilt up and out of the tip (503) and createmisalignment between the lock wire lumens of the tip (503) and theshuttle (516) are minimized or prevented. Accordingly, utilizing thedescribed recess (510) may prevent or minimize interference between thesurfaces of the recess (510) and the distal portion (514) of the snare,which may make the closure device easier to manufacture by providingbetter and more consistent alignment of the lock wire lumen openings.Additionally, utilizing the described recess (510) may prevent orminimize tissue from becoming caught or pinched between the tip (503) ofthe elongate body and the distal portion (514) of the snare positionedin the recess (510). In particular, because the distal portion (514) ofthe snare may bend freely without interference from the tip (503),pinching of tissue between the distal portion (514) and the tip (503)may be substantially reduced. Accordingly, both the ease of use of theclosure device during a procedure and the assembly of the closure devicemay be improved as alignment and fit of the retractable snare isimproved.

In another variation, the recess may be in the form of a channelcomprising an increasing width from the front surface of the shuttlerecess to the front surface of the tip. For example, in thesevariations, a proximal portion of the channel adjacent to or at theshuttle recess (e.g., aligned with the front surface of the shuttlerecess) may be narrower than a distal portion of the channel adjacent toor at the distal end of the tip (e.g., aligned with the front surface ofthe tip). Thus, the recess may be in form of a tapered channel.Utilizing a recess with increasing width distally along a longitudinalaxis of the tip (502) may assist in holding the shuttle (516) within theshuttle recess (509) but may still allow the distal portion (514) of thesnare to bend freely (e.g., without being constrained by the walls ofthe recess).

FIG. 5C shows a top view of the tip (503) with a shuttle recess (509) inwhich the shuttle (516) may be positioned. As shown, the lock wire (520)may be positioned within the lock wire lumen and the window or lock wirerecess (518) of the shuttle (516). The distal portion (514) of the snaremay be in contact with the first and second surfaces (511, 513) of therecess (510) of the tip (503) and otherwise unencumbered to allow thedistal portion (514) to be manipulated without interference or contactfrom the tip (503). When the shuttle (516) is coupled to the tip (503)of the elongate body within the shuttle recess (509), a clearancebetween the shuttle (516) and the tip (503) may be about 0.004 inches(0.102 mm) total. For example, in some variations, the shuttle may havea width of about 0.060 inches+0.001/−0.002 inches (1.524mm+0.0254/−0.0508 mm) and a length of about 0.183 inches±0.003 inches(4.648 mm±0.0762 mm) and the shuttle recess (509) may have a width ofabout 0.070 inches±0.003 inches (1.778 mm±0.0762 mm) and a length ofabout 0.190 inches±0.003 inches (4.826 mm±0.0762 mm), which may resultin a shuttle clearance of between about 0.003 inches (0.0762 mm) andabout 0.0075 inches (0.1905 mm) on each side of the shuttle, and ashuttle clearance of between about 0.0005 inches (0.0127 mm) and about0.0065 inches (0.1651 mm) at the proximal and distal ends of theshuttle. In some variations, the shuttle clearance on each side of theshuttle may be about 0.005 inches (0.127 mm) and the shuttle clearanceon each of the proximal and distal ends may be about 0.0035 inches(0.0889 mm).

Shuttle

As described above, in some variations, a shuttle may be provided in asnare loop assembly (e.g., coupled to a distal portion or end of thesnare) to allow a distal portion of a snare loop to be released from atip of the elongate body and retracted into a lumen of the tip and/orelongate body. While a diameter of the snare may generally be smallerthan a diameter of a tip or elongate body lumen, and thus may passeasily into the lumen, one disadvantage of other shuttle configurationsis their inability to retract into a lumen, thus preventing retractionof the snare into a tip and/or elongate body. Consequently, when usingdevices with other shuttle configurations, the shuttle and the snareloop attached thereto are at risk of being caught on anatomical featuresand the deployed suture as the closure device is retracted from thetarget tissue.

In contrast to other devices, the closure devices described herein maycomprise a shuttle that is configured to fit through a lumen in the tipand/or elongate body. For example, a device for closing a target tissuemay comprise an elongate body comprising a lumen therethrough, a snareloop assembly comprising a snare and a suture loop releasably coupled tothe snare, and a shuttle connected to a distal portion of the snare andreleasably coupled to the elongate body that may comprise aconfiguration to fit into the lumen of the elongate body. Put anotherway, the shuttle may be configured to retract into a lumen of the tipand/or the elongate body.

For instance, after a shuttle is released from the tip of the elongatebody (e.g., from a shuttle recess in the tip), the snare loop and theshuttle may be partially or completely retracted into the closure devicesuch that the no portion of the snare or shuttle extends out of thelumen or only a small portion of the snare and/or shuttle extends out ofthe lumen. In some variations, the closure device may be configured suchthat the entirety of the snare and the shuttle may be retracted into alumen of the tip and/or elongate body, while in other variations, theclosure device may be configured such that the snare partially retractsinto the lumen such that all or a portion of the shuttle remains outsideof the tip/elongate body (i.e., is not retracted into the lumen). Thispartial or full retraction reduces the likelihood of tissue pinchingand/or catching on the deployed suture. Additionally, partial or fullretraction of the snare also reduces the risk of the snare being caughton anatomical features. In this manner, the closure devices describedherein may be retracted from the target tissue and removed from the bodymore safely.

As mentioned above, in some variations, the closure devices describedhere may comprise a shuttle that is configured to partially retract intoa lumen of the tip and/or elongate body of the closure device. Forexample, FIG. 18 is a perspective view of a variation of a closuredevice (1800) having a partially retracted snare. The closure device(1800) may comprise an elongate body (1801) comprising a tip (1802), afirst lumen (1804), and a second lumen (1806), a shuttle (1816), and asnare (1814) (only a distal portion of the snare is depicted). Theshuttle (1816) may be connected to the distal portion of the snare(1814). Although not depicted in FIG. 18, the snare (1814) may bereleasably coupled to a suture loop, for example, via a retentionmember, before deployment of the suture loop. When the suture loopcomprises a suture knot (not shown), the suture knot and a tail of thesuture loop may be positioned in and/or extend through the second lumen(1806). The tip (1802) may additionally comprise a lock wire lumen(1808) that may be configured to receive a lock wire that may secure theshuttle (1816) relative to the tip (1802) and the elongate body (1801).The tip (1802) may comprise a shuttle recess (1812), in which theshuttle (1816) may be positioned and housed when the shuttle (1816) iscoupled to the tip (1802). The tip (1802) may further comprise anapproximately L-shaped recess (1810) in a side wall of the tip (1802).

In the variation shown in FIG. 18, the snare (1814) may be fully orpartially retractable into the first lumen (1804), while the shuttle(1816) may be partially retractable into the first lumen (1804). Forexample, the diameter of the snare may be smaller than a diameter of thefirst lumen (1804), and a maximum transverse dimension (transverse tothe longitudinal axis of the snare) of at least a portion of the shuttle(1816) (e.g., a height, width, or a diameter) may be larger than thediameter of the first lumen (1804). For example, the shuttle (1816) maycomprise a first proximal portion (1815) coupled to the distal portionof the snare (1814) and a second distal portion (1817). In somevariations, the first proximal portion (1815) may have a maximumtransverse dimension that is smaller than a diameter (and/orheight/width) of the first lumen (1804) and the second portion (1817)may have a maximum transverse dimension that is larger than the diameter(and/or height/width) of the first lumen (1804). In other variations,the first portion of the shuttle (1816) may have a smallercross-sectional area than a cross-sectional area of the first lumen(1804), while the second portion of the shuttle (1816) may have a largercross-sectional area than the cross-sectional area of the first lumen(1804), such that the second portion of the shuttle (1816) may not fitwithin the first lumen (1804). In yet other variations, the secondportion of the shuttle (1816) may comprise a width that is larger thanthe diameter (or width) of the first lumen (1804), which may prevent thesecond portion of the shuttle from being retracted into the first lumen(1804). Thus, in some variations, the distal portion of the snare (1814)may be partially (as shown) or fully retracted into the first lumen(1804), while the shuttle (1816) may only be partially retracted intothe first lumen (1804) (or in some variations, remain fully exposed butpositioned closer to/just distal of a distal end of the elongatebody/tip).

In other variations, as will be described in detail herein, the closuredevices described here may comprise a shuttle that is sized and shapedto fully retract into a lumen of the tip and/or the elongate body of theclosure device. In these variations, a maximum transverse dimension ofthe shuttle may be less than a diameter (and/or height/width) of thelumen of the tip and/or elongate body. For example, FIGS. 9A and 9B areperspective views of a variation of a shuttle that is configured tofully retract into a lumen of the tip and/or the elongate body. Asdescribed above, the shuttle may be connected to a distal portion of thesnare and may be releasably coupled to the tip of the elongate body. Theshuttle (900) may comprise a first lumen (902, 910), a second lumen(904), a window or lock wire recess (906), and a projection (908). Thefirst lumen (902, 910) may comprise a lock wire lumen with a distalportion (902) and a proximal portion (910) separated by the lock wirerecess (906). A lock wire (not shown) may be advanced through orotherwise disposed in the lock wire lumens (902, 910) and the lock wirerecess (906) to releasably couple the shuttle (900) to the elongatebody. The projection (908) may be configured to engage with acorresponding track in a shuttle recess of a tip (e.g., track (416) of ashuttle recess (408)). This engagement may minimize rotation of theshuttle (900) relative to the tip when external forces are applied tothe snare loop.

A user may use the closure device to pull the shuttle (900) into a lumenof the elongate body when the snare is fully retracted. The shuttle maycomprise a configuration to fit into the lumen. The shuttle may comprisevarious sections or portions with different characteristics, forexample, different diameters, cross-sectional areas, cross-sectionalshapes, materials, and the like, which may improve the fit andslidability of the shuttle in the lumen. For example, at least someportions of a cross-section of the shuttle may correspond to the shapeof the lumen. In some variations, a radius of curvature of at least aportion of the shuttle may be the same as a radius of curvature of thelumen. The shuttle may comprise any suitable length allowing the shuttleto be releasably coupled to the elongate body and to fit into the lumen.The shuttle may also comprise any suitable configuration to couple witha lock wire, such as a lock wire lumen and optionally a window or lockwire recess. For instance, the shuttle (900) may comprise a lock wirerecess (906) comprising a width between about 0.015 inches (0.381 mm)and about 0.025 inches (0.635 mm).

FIG. 10 is a sectional view of a variation of a shuttle in a lumen of atip of a closure device. As mentioned above, in some variations, theshuttle (1000) may comprise a shuttle diameter that is less than adiameter of a lumen (1010) of the tip (e.g., the first lumen (1804) inFIG. 18). This configuration allows the shuttle (1000) to fully retractinto the lumen when the snare is fully retracted. For example, in onevariation, the shuttle (1000) may comprise a radius between about 0.015inches (0.381 mm) and about 0.030 inches (0.762 mm). In some variations,the shuttle (1000) may comprise a radius of about 0.030 inches (0.762mm). In these variations, the lumen may comprise a radius of about 0.031inches (0.80 mm), and thus, the radius of the shuttle (1000) may be lessthan the radius of the lumen (1010). In these variations, the shuttle(1000) retracted into the lumen (1010) has a clearance fit. A clearancefit may be a positive difference between a size of the lumen (e.g.,diameter, height, width) and a size of the shuttle (e.g., a dimension(height, width, diameter) of the largest portion of the shuttle). Inother variations, the shuttle diameter may be equal to the diameter ofthe lumen (1010) and or may be slightly larger than the diameter of thelumen (1010), but the shuttle may be configured to compress or otherwisedecrease in size in order to fit within the lumen (1010).

The shuttle (1000) may comprise a first lumen (1002), a second lumen(1004), and a projection (1008). The second lumen (1004) may comprise asnare lumen where FIG. 10 illustrates a distal portion of the snarelumen. The snare lumen may house a portion of the snare such that theshuttle (1000) is coupled to a distal portion of the snare. A proximalportion of the second lumen (1004) may comprise an offset obround shape(1006) and a distal portion of the second lumen may comprise a circularshape. In one variation, a proximal portion of the snare lumen comprisesan offset obround shape. An end of the snare may comprise a flattenedportion (not shown) configured to fit within the obround shape (1006).In these variations, the use of a lumen with obround and circularportions may assist in preventing the flattened portion of the snarefrom pulling out of or breaking through the second lumen (1004) (e.g.,from the obround portion to the circular portion) and coming out of theshuttle (1000). The flattened portion may further be bonded to theobround shape (1006) to prevent the snare from pulling through thesecond lumen (1004) as well as preventing the snare from rotatingrelative to the shuttle. The obround shape (1006) may be filled withadhesive, such as epoxy, to bond the flattened portion of the snare tothe shuttle (1000). The first lumen (1002) may comprise a lock wirelumen and may be sized and shaped for passage of a lock wiretherethrough. In some variations, the diameter of the lumen (1010) ofthe elongate body may be equal to or less than about 0.063 inches (1.60mm). The shuttle diameter may be equal to or less than about 0.061inches (1.56 mm).

The shuttle may be formed from any suitable material or materials, suchas, for example, one or more metals (e.g., stainless steel), one or morerigid plastics, one or more polymers, or the like. In some variations,the shuttle may be formed from the same material or materials as aportion of the tip or elongate body, but need not be. In somevariations, the shuttle may be formed from one or more of polyetherimide(e.g., Ultem®), polycarbonate, and stainless steel.

Handle

As described above, the closure devices described here may comprise ahandle or other control mechanism. The handle may have any suitableshape or configuration, for example, any of those described in U.S.patent application Ser. No. 12/752,873, entitled “Tissue LigationDevices and Controls Therefor” and filed on Apr. 1, 2010, which waspreviously incorporated by reference, or U.S. patent application Ser.No. 14/195,797, entitled “Tissue Ligation Devices and Methods Therefor”and filed Mar. 3, 2014, the entire content of which is herebyincorporated by reference herein.

The handle may serve many purposes. Of course, the handle may provide aninterface between the device and the user as the user may hold onto andcontrol the device and its components using the handle. The handle maybe used to control and actuate the snare loop assembly through theelongate body, guide the elongate body, and/or modify the shape of theelongate body using a pull wire controlled through the handle. Thehandle may enable a user to control the release of the suture loop fromthe closure element, and in variations in which a visualization tool isused, it may be used to house electronic or other components for thevisualization tool. The handle may comprise any suitable elements tofacilitate use of the device for the closure of tissue, includingsliders, knobs, switches, latches, push buttons, and the like, which maybe coupled to any component of the snare loop assembly to pull, push,open, close, deploy, or otherwise use the component.

In some embodiments, the handles of the closure devices described heremay comprise a tensioning mechanism for managing the tension applied toa portion of the suture loop (e.g., a tail of the suture loop) of theclosure device. When the closure devices are used to place and tighten asuture loop around a tissue, it may be desirable to manage the tensionapplied to the suture as the suture loop is tightened.

When the closure devices described comprise a snare that is temporarilyfixed to the elongate body via a shuttle and a lock wire, the handle maycomprise a mechanism that allows for withdrawal of the lock wire, andthe lock wire may be withdrawn in any suitable manner. Current solutionsdo not provide a mechanism for full retraction of the snare andoptionally the shuttle with safeguards that prevent premature retractionof the snare loop initiated by user error. The handle assembly andvariations described in detail below allow a shuttle and snare loop tobe fully retracted through or into the tip and/or the elongate body in adesired order that may assist in preventing user error. For example, adevice for closing a target tissue may comprise an elongate body, asnare loop assembly comprising a snare and a suture loop releasablycoupled to the snare, a shuttle configured to releasably couple to theelongate body, and a handle comprising a lock or a snare control with alimiter, which of which may be configured to limit movement of the snarecontrol along a track.

FIGS. 11A-11B and 11D-11E are perspective views of an illustrativevariation of a handle assembly for use with the closure devicesdescribed here. A handle (1104) of the handle assembly (1100) may beattached to the elongate body (1102). The handle (1104) may comprise asnare control (1106) configured to control movement of the snare (notshown), a track (1108), which may be formed on a side, top, or bottomthereof, and a lock (1110). The handle assembly (1100) may furthercomprise a suture control (1112) configured to tighten the suture loop.The suture control (1112) may be releasably coupled to the handle (1104)via a first opening (1118) and a second opening (1120). The snarecontrol (1106) may comprise a slider and may be coupled to and slideablydisposed within or on the track (1108). The track (1108) may comprise afirst portion (1109) and a second portion (1116), and the lock (1110)may be configured to limit movement of the snare control (1106) alongthe second portion (1116) of the track. The device may be configuredsuch that the snare control (1106) may freely move/slide along the firstportion (1109) of the track to open or close a snare loop assemblyregardless of whether the lock (1110) is engaged (i.e., when the lock isengaged and when the lock is disengaged), but may be prevented frommoving/sliding along the second portion (1116) of the track when thelock (1110) is engaged. The handle (1104) may further comprise a sideopening (1114) aligned with at least a portion of the second portion(1116) of the track.

The lock (1110) may physically limit retraction of the snare prior torelease of the shuttle from the elongate body (1102). For example, thelock (1110) may comprise a stopper (1115) that extends along a length ofthe track. For example, the stopper (1115) may fit over and/or withinthe second portion (1116) of the track and may prevent the snare control(1106) from moving along or within the second portion (1116) of thetrack. In some variations, the stopper (1115) may comprise a rectangularplate that covers the second portion (1116) of the track, while in othervariations, the stopper may comprise a cylindrical or other shapedelement that fits within, covers, or otherwise blocks the track and/orprevents the snare control (1106) from moving proximally along thesecond portion (1116) of the track.

Additionally, in some variations, the lock (1110) may further comprise arelease engagement portion (1111) configured to limit movement of thesnare control (1106) along a second portion (1116) of the track (1108)until after release of the suture. In these variations, the releaseengagement portion (1111) may releasably couple to a release assemblywithin the handle. The release assembly may be configured to release ashuttle (not shown) from the elongate body (1102) and may hold the lock(1110) in position in or on the track (1108) until after release of thesuture, as will be described in more detail below. In some variations,the release engagement portion (1111) may comprise a protrusion that mayextend from the underside (e.g., bottom surface) of the stopper (e.g.,at an approximately 90 degree angle) and may comprise an opening (1113)that may releasably couple to a portion of the release assembly.

FIG. 11A depicts a lock (1110) covering the second portion (1116) of thetrack (1108), which limits movement of the snare control (1106) alongthe second portion (1116) of the track (1108). FIG. 11B depicts the lock(1110) removed from the second portion (1116) to allow movement of thesnare control (1106) along the second portion (1116) of the track(1108). FIG. 11C is a top view of the handle assembly shown in FIG. 11B.FIG. 11D illustrates the snare control (1106) moved along the track(1108) to a position adjacent the second portion (1116). FIG. 11Eillustrates the snare control (1106) moved to a proximal end of thetrack (1108). The snare control (1106) is configured to retract thesnare and the shuttle into the elongate body (1102) when the snarecontrol (1106) moves along the second portion (1116) of the track(1108), such as to the proximal end of the track (1108).

A proximal portion of the suture control (1112) may be configured toengage the release assembly through the opening (1114) in the handle torelease the lock (1110) from the track (1108) and allow movement of thesnare control (1106) along the second portion (1116) of the track(1108). Additionally, or alternatively, the suture control (1112) may beconfigured to engage the release assembly to retract a lock wire thatreleasably couples the shuttle to the elongate body (1102).Additionally, or alternatively, the suture control (1112) may beconfigured to engage the release assembly to release the shuttle fromthe elongate body (1102). In some variations, the closure device may beconfigured such that when the suture control (1112) engages the releaseassembly, the lock (1110) is released and the lock wire issimultaneously retracted, thereby releasing the shuttle from theelongate body (1102). Thus, in some variations, the lock (1110) may bereleased from the track (1108) and thus the handle (1104) and theshuttle may be released from the elongate body simultaneously.

FIG. 12 shows a perspective view of a suture control (1200) for use witha handle assembly such as the handle assembly (1100) described withrespect to FIGS. 11A-11D. The suture control may comprise a body (1202)configured to be gripped or held by a hand of a user and one or moreprojections. For example, the suture control may comprise a first,longer, elongate portion (1204) that may be inserted into a handle, anda second, shorter, elongate portion (1206) that may be coupled to thesuture. The first portion (1204) may be longer than the second portion(1206) such that when the first portion is inserted into a side openingin the handle (for example, the side opening (1114) depicted in FIG.11A), the second portion (1206) does not interfere or otherwise preventthe first portion (1204) from engaging the release assembly.Additionally, the first portion (1204) may comprise a diameter that issmaller than the diameter of the side opening, such that the firstportion (1204) may be advanced through the side opening to engage therelease assembly. In other variations, the suture control (1200) maycomprise a single projection or elongate portion that may both couple tothe suture to release the suture from the snare loop assembly and/ortighten the suture, and be inserted into a side opening in the handle toengage with a release assembly (e.g., to release the shuttle and unlockthe lock). The suture control (1200) may also couple to a distal endsurface of the handle (e.g., through insertion of the one or moreprojections through openings in the distal end surface), as depicted inFIG. 11A. Additionally, while the suture control (1200) is depicted withcylindrical projections, the one or more projections may have anysuitable cross-sectional shape, for example, oval, square, rectangular,hexagonal, and the like.

FIGS. 13A-13B are cross-sectional perspective views of a variation of ahandle assembly (1300) of a closure device. A bottom cover of the handle(1302) is not shown in FIGS. 13A-13B in order to illustrate an undersideof the inner portion of the handle assembly (1300), such as theunderside of the track (1308) and the lock (1310). The handle (1302) maycomprise an opening (1304) to guide at least a portion of a suturecontrol (not shown) into the handle (1302) to engage with a releaseassembly (1320). As described above with respect to FIGS. 11A-11D,movement of the snare control along the track (1308), for example, asecond portion of the track, may be limited by the lock (1310) when thelock is coupled to the handle and positioned on or within the track(1308). The handle (1302) may further comprise a release assemblyhousing (1316) and a release assembly housing track (1318) which definethe path of movement for the release assembly (1320) and guide therelease assembly (1320) along a linear path laterally toward an oppositeside of the handle when a portion of the suture control engages with therelease assembly (1320).

As shown in FIG. 13A, the lock (1310) may comprise an end plate (1312)at a proximal end thereof and a lock engagement portion (1314). The lockengagement portion (1314) may comprise an opening configured to receiveat least a portion of a release engagement portion. Insertion of atleast a portion of the suture control into the opening (1304) may unlockthe lock (1310) from the track (1308) by disengaging the lock engagementportion (1314) from a portion of the release assembly (1320) (e.g., therelease engagement portion). Insertion of at least a portion of thesuture control into the opening (1304) may also pull the lock wireproximally, which may retract the lock wire from the lock wire lumen inthe shuttle and release the shuttle from the elongate body. The unlockedlock (1310) may be manually removed from the track (1308), which mayclear the second portion of the track so that the snare control may movealong a second portion of the track (1308). The end plate (1312) maycomprise an L-shaped structure that may be configured to couple to anotch or channel (1309) in the track (1308).

The release assembly (1320) may comprise a release engagement portion(1324) configured to releasably couple to the lock engagement portion(1314) of the lock (1310). When the release engagement portion (1324) iscoupled with the lock engagement portion (1314), movement of the snarecontrol may be limited, as the lock may block or otherwise prevent thesnare control from moving along or through the second portion of thetrack. Thus, when the release engagement portion (1324) is coupled withthe lock engagement portion (1314), the snare and shuttle may not befully retracted into a lumen of the tip and/or the elongate body.

In some variations, the release engagement portion (1324) may comprise abase (1323) and a protrusion (1325) that extends therefrom, and theprotrusion (1325) may be configured (e.g., sized and shaped) to fitwithin an opening in the lock engagement portion (1314). In somevariations, the protrusion (1325) may comprise a circularcross-sectional shape, and a diameter of the protrusion (1325) may beless than the length/width/diameter of the base (1323), however, thelength or height of the protrusion (1325) may be greater than a heightof the base (1323). The base (1323) may have any suitablecross-sectional shape, for example, square, rectangular, circle, oval,and the like. In other variations, the release engagement portion (1324)may comprise an elongate member comprising a circular cross-sectionalshape without a discrete or discernable base. The diameter of theelongate member may be constant along the longitudinal axis of theelongate member (e.g., from a proximal to a distal end of the elongatemember). In these variations, the elongate member and/or the entireengagement portion (1324) may be configured to fit within an opening ofthe lock engagement portion (1314). In some variations, the protrusion(1325) and/or the entire release engagement portion (1324) may have anon-circular cross-sectional shape, for example, square, rectangular,oval, hexagonal, octagonal, or the like. In some embodiments, therelease engagement portion (1324) may comprise one or more notches,grooves, and/or indentations on an external surface thereof (e.g., alonga length and/or around a circumference thereof), which may in someinstances assist with establishing or maintaining contact between therelease engagement portion (1324) and the lock engagement portion (1314)of the lock (1310). In variations comprising a base and a protrusion,the notches, grooves, and/or indentations may be on the on theprotrusion (1325) and optionally on the base (1323).

The release assembly (1320) may also comprise a lock wire engagementportion (1322) (e.g., a post around which the lock wire may be wound, ascrew, or the like), which may couple a proximal end of the lock wire tothe release assembly (1320). As described above, the distal end of thelock wire may be disposed within lock wire lumens in the shuttle and thetip or elongate body, which may releasably couple the shuttle to theelongate body.

FIG. 13A illustrates the release assembly (1320) prior to advancement ofat least a portion of a suture control through the opening (1304) in thehandle (1302). Thus, the lock (1310) in FIG. 13A is engaged and a useris prevented from retracting the snare control through the secondportion of the tract to retract the snare and shuttle into a lumen ofthe device. When the lock is engaged, the stopper of the lock (1310) maybe coupled to the track (1308) through the coupling of the lockengagement portion (1314) of the lock (1310) and the release engagementportion (1324) of the handle (1302). In this configuration, the endplate (1312) may also be coupled to the notch (1309) in the track(1308).

FIG. 13B illustrates the handle assembly (1300) after the suture controlhas been advanced through the opening (1304) and has engaged the releaseassembly (1320) to release the lock wire and the lock (the lock has beenremoved for clarity). In particular, the release assembly (1320) hasbeen guided to a second end (opposite a first end adjacent to theopening (1304)) of the releasable assembly housing track (1318) withinthe releasable assembly housing (1316) to uncouple the releaseengagement portion (1324) from the lock engagement portion (1314) of thelock (1310). Accordingly, the lock (1310) may be removed from the track(1308) to thereby allow movement of the snare control along a secondportion of the track (1308). The movement of the release assembly (1320)along the release assembly housing (1316) also draws in the lock wire torelease the shuttle from the elongate body at a distal end of theclosure device. Thus, in some variations, movement of the snare controlmay be limited by the lock until the suture is released, the suturecontrol is decoupled (e.g., cut) from the suture, and at least a portionof the suture control is advanced through the opening to engage (e.g.,push, move in a direction transverse to the longitudinal axis of thehandle) the release assembly. Accordingly, in this way, prematureretraction of a snare loop and the shuttle (e.g., prior to release ofthe suture loop from the snare loop assembly and/or prior to release ofthe shuttle from the elongate body) may be prevented. While it may beuseful in some variations to prevent release and retraction of theshuttle prior to release of the suture loop from the snare loopassembly, the suture loop need not be deployed from the snare loopassembly prior to release and retraction of the shuttle in allinstances.

FIGS. 14A and 14C are cross-sectional perspective views of anothervariation of a handle assembly (1400) of a closure device. In thisvariations, in place of the lock (1310) shown in FIG. 13A, the snarecontrol (1412) may comprise a limiter (1416) configured to limitmovement of the snare control along the track (1404) until a suturecontrol (1422) is inserted into the handle (e.g., via a side opening).FIG. 14B is a cross-sectional side view of the handle assembly shown inFIG. 14A. A bottom cover of the handle (1402) is not shown in FIGS. 14A,14B, and 14C in order to illustrate an underside of the inner portion ofthe handle assembly (1400), such as the underside of the track (1404)and snare control (1412).

The handle (1402) may comprise an opening (not shown) to enable andguide a suture control (1422) to engage with a release assembly (1418)within the handle (1402). The handle (1402) may further comprise arelease assembly housing (1406) to guide movement of the releaseassembly (1418) along a release assembly housing track (1408) while thesuture control (1422) engages the release assembly (1418). The snarecontrol (1412) may comprise a slider (1413), a track engagement portion(1414) coupled to the slider (1413) via a spring and slideably couplingthe slider (1413) to the track (1404), a snare coupler (1415) (e.g., abracket or the like) coupling a proximal end of the snare to the snaretrack engagement portion (1414) of the snare control (1412), and alimiter (1416) coupled to or formed integrally with a proximal portionof the snare track engagement portion (1414) and configured to limitmovement of the snare control along the track (1404). The slider (1413)may be configured to be advanced and retracted by a hand of the user(e.g., a thumb) when the device is in use.

The limiter (1416) may extend along a length of the handle (e.g., alonga longitudinal axis thereof) sufficient to provide retraction of thesnare and shuttle into the elongate body through movement of the snarecontrol (1412) along the track (1404). The limiter (1416) may beprovided on a non-overlapping parallel plane with respect to the releaseassembly (1418) so as to allow the limiter (1416) to travel over therelease assembly (1418) (and the release assembly housing (1406) whenthe slider (1512) is facing upward toward a user (under the releaseassembly in the configuration shown) when disengaged from the releaseassembly (1418), as shown in FIG. 15A. The release assembly (1418) maybe configured to release the shuttle from the elongate body and allowmovement of the snare control (1412) along the track.

The suture control (1422) may be configured to tighten the suture loopand may comprise a proximal portion. The proximal portion may beconfigured to engage the release assembly (1418) through an opening inthe handle and may comprise a projection (1424). When the projection(1424) engages the release assembly (1418), the limiter (1416) may bedisengaged from the release assembly (1418). For instance, the releaseassembly (1418) may comprise an engagement portion (1420) and the suturecontrol (1422) may be configured to engage the release assembly (1418)to disengage the limiter (1416) from the release assembly (1418), asshown in FIG. 14C. In particular, the engagement portion (1420) maydisengage from the limiter (1416) to allow movement of the snare control(1412) along the track (1404). In some variations, disengaging thelimiter (1416) may comprise moving the engagement portion (1420) forexample, in a direction transverse to a longitudinal axis of the handle(1402), from a first location in which it blocks or otherwise preventsproximal movement of the limiter (1416) to a second location in which itno longer blocks or otherwise prevents proximal movement of the limiter(1416). In this variation, the engagement portion (1420) may serve as aphysical stop or barrier. Thus, engaging the release assembly (1418)with at least a portion of the suture control (1422) may move theengagement portion (1420) out of a pathway of the limiter (1416) suchthat the limiter (1416) may move to a location proximal of theengagement portion (1420). In the variation shown in FIG. 14C, theengagement portion (1420) is disengaged from the limiter (1416) and maybe positioned in another opening in the handle (1402).

The suture control (1422) configured to engage the release assembly(1418) may release the shuttle from the elongate body. In somevariations, the suture control (1422) may simultaneously disengage theengagement portion (1420) of the release assembly (1418) from thelimiter (1416) and release the shuttle from the elongate body.

The handle (1402) may further comprise a flexible latch (1410)configured to allow movement of the release assembly (1418) duringinsertion of the suture control (1422) into the handle (1402), andconfigured to limit movement of the release assembly after engagement ofthe suture control (1422) to the release assembly (1418). As shown inFIG. 14A, as the suture control (1422) is inserted into the handle(1402), the flexible latch (1410) may engage the release assembly (1418)and bend enough to allow the release assembly (1418) to be pushed to anend of the release assembly housing track (1408). However, as shown inFIG. 14C, upon completed insertion of the projection (1424) into theopening, the flexible latch (1410) may return to its original positionand engage with a first side surface (i.e., a surface closest to theopening in the handle through which the suture control (1422) isinserted) of the release assembly (1418) in such a manner as to preventthe release assembly (1418) from reverse movement along the releaseassembly housing track (1408) towards the opening.

FIG. 15A is a cross-sectional perspective view of a variation of ahandle assembly (1500) of a closure device. FIG. 15B is across-sectional side view of the handle assembly shown in FIG. 15A.FIGS. 15A-15B illustrate the movement of the snare control (1512) to anend of the track (1504) after engagement of the suture control (1522)disengages the release assembly (1518) from the limiter (1516) of thesnare control (1512). The suture control (1522) need not remain in thehandle (1502) once inserted, and is provided in FIGS. 15A-15B merely forillustrative purposes.

The snare control (1512) may comprise a slider (1513) or other elementconfigured to interface with a user, a track engagement portion (1514)slideably coupling the snare control (1512) to the track (1504), a snarecoupler (1515), and a limiter (1516). The suture control (1522) maycomprise a projection (1524) insertable into an opening (not shown) ofthe handle (1502), which may engage with the release assembly (1518).The handle (1502) may comprise a release assembly housing (1506) thatmay guide the release assembly (1518) along a housing track (not shown)as the suture control (1522) is inserted into the housing (1502) via theopening. An engagement portion (1520) is shown disengaged from thelimiter (1516) to allow movement of the snare control (1512) along thefull length of the track (1504). Additionally, the handle (1502) mayalso comprise a latch (1510) similar to the latch (1410) described abovewith respect to FIGS. 14A-14C.

II. Methods

The closure devices described here may be useful for closing tissue, forexample, the left atrial appendage. The closure devices may access theleft atrial appendage using percutaneous or surgical techniques (e.g.,median sternotomy, mini sternotomy, thoracotomy, thoracoscopy). One ormore guides having alignment members may be advanced to the left atrialappendage. These guides may be any suitable guide, such as thosedescribed in U.S. Pat. No. 8,771,297, entitled “Devices, Systems, andMethods for Closing the Left Atrial Appendage” and filed on Mar. 25,2008, which is incorporated by reference herein in its entirety. Forexample, first and second guides having alignment members may be used toguide the procedure. The alignment members may be any suitable alignmentmembers (e.g., interconnecting elements, one or more vacuum members,radiopaque or echogenic markers, members that are configured to producean audible response, magnets, and the like). In some variations, thealignment members may be magnets located at the distal ends of theguides. These guides may be used for guiding additional tools and/ordevices (e.g., the closure device) to the left atrial appendage.

For example, in some variations, a first guide may be advanced into theleft atrial appendage, while the second guide may be advanced into thepericardial space adjacent to the left atrial appendage. Either of theseguides may be advanced under any of a variety of visualizationtechniques, such as fluoroscopic visualization, ultrasoundvisualization, or some combination thereof. Once the first and secondguide members have been advanced to the left atrial appendage, one ormore positioning and/or stabilizing elements (e.g., balloons or otherexpandable structures) may be advanced over or in conjunction with thefirst guide (e.g., it may be coupled to or be part of the first guide)and into the left atrial appendage. Similarly, a closure device may beadvanced over the second guide to the exterior of the left atrialappendage. It should be appreciated that the closure device may be anyof the closure devices described above.

When placed in the left atrial appendage, the positioning element may beused to help position the snare loop of the closure device. In somevariations, an expandable structure may be inflated or otherwiseexpanded in or near the opening of the left atrial appendage and thesnare loop may be closed around the left atrial appendage distal to theexpandable structure. In other variations, the expandable member may beexpanded inside of the left atrial appendage. In these variations, theexpandable member may help position the closure device near the base ofthe left atrial appendage.

While the expandable member is in an expanded state, the snare loop maybe opened and may be placed around a portion of the left atrialappendage. Once placed around the left atrial appendage, the snare loopmay be closed around the left atrial appendage.

A distal end of an elongate body may be advanced into the body toward atarget tissue (e.g., the left atrial appendage). During advancement, thesnare loop assembly may be in a closed configuration to help prevent thesnare loop assembly from snagging or catching on tissue or otherobstructions. Once the distal end of the elongate body has reached alocation at or near the target tissue, the snare loop assembly may beopened to a deployed configuration. The snare loop assembly may then beadvanced, moved, or otherwise manipulated to encircle at least a portionof the target tissue. The snare loop assembly may then be closed aroundthe encircled tissue to close, ligate, or otherwise restrict the targettissue. The snare loop assembly may be re-opened, repositioned, andre-closed as necessary.

In some instances, a suture loop or other restricting device may betightened and released from the closure device to maintain the targettissue in a closed fashion. To remove the closure device from the body,the snare loop assembly (e.g., the snare and optionally a retentionmember) may again be opened to release the target tissue (the sutureloop or other restricting device may remain in place) such that thesnare loop assembly and the elongate body may be withdrawn. The snareloop assembly may be released for retraction into the elongate body. Invariations where the closure device comprises a retraction device ormechanism, the retraction device or mechanism may be used to release thesnare and shuttle from the elongate body and retract the snare andshuttle into the elongate body.

In some variations using the devices described here, the methods maycomprise fully retracting the snare and shuttle into the elongate bodysuch that no portion, or just a small portion, of the snare and theshuttle remain exposed outside the elongate body. The methods describedherein may ensure the release of the suture loop from the snare andretraction of the snare and shuttle from the tip in a manner thatprevents an operator from prematurely retracting the snare and shuttleprior to releasing the shuttle from the tip. FIGS. 16A-16G and 17A-17Gmay more clearly demonstrate these concepts. In FIGS. 16A-16G, a shuttleis released and retracted before tightening a suture loop. In FIGS.17A-17G, a shuttle is released and retracted after tightening a sutureloop.

FIG. 16A is a flowchart (1600) for one variation of a tissue closingprocess using the devices described herein. FIGS. 16B-16G areperspective views of a snare loop assembly and handle corresponding tothe various steps in FIG. 16A. The flowchart (1600) begins withadvancement of a closure device towards target tissue (1602). Onceadvanced to a desired position, a snare loop assembly may be closedaround the target tissue (1604), as illustrated in FIGS. 16B and 16C.FIG. 16B illustrates an elongate body (1620) comprising a tip (1622),and a snare loop assembly (1624) comprising a shuttle (1626) positionedwithin a shuttle recess of the tip (1622). While the snare loop assembly(1624) is depicted without a suture loop and a retention member, thesnare loop assembly may comprise both a suture loop and a retentionmember. The snare loop assembly (1624) is illustrated in the closedposition, and the position of the snare loop assembly (and the size ofthe aperture formed by the snare loop assembly) may be modified by useroperation of the handle (1628) shown in FIG. 16C. The snare control(1630) may slide along a track, but may be prevented from initiatingretraction of the snare loop assembly (1624) and the shuttle (1626) intothe elongate body (1620) and/or tip (1622) by a lock (1632) as depicted(and described in more detail with respect to FIGS. 11A-11D and13A-13B), or a limiter as described in more detail with respect to FIGS.14A-14B and 15A-15B. The snare loop assembly (1624) may be opened andclosed as necessary to ensure that the target tissue is properlyligated. The handle (1628) may further comprise a suture control (1634)for tightening a suture loop, releasing the lock (1632) from the track,and/or releasing the shuttle (1626).

After the snare loop assembly (1624) is determined to be positionedproperly relative to the target tissue and is closed around the targettissue, the suture loop (not depicted) may be released (1606) from thesnare loop assembly (1624). A user may pull the suture control (1634)out from a base of a handle (1628) in order to release the suture loopfrom the snare loop assembly (1624). As least a portion of the suturecontrol (1634) may then be inserted into an opening (e.g., a sideopening) in the handle (1628) to engage the release assembly within thehandle (1628), release (1608) the shuttle (1626) from the elongate body(1620), and unlock the lock (1632). FIGS. 16D and 16E depict the shuttlereleased from the shuttle recess of the tip (1622) of the elongate body(1620), and the lock (1632) unlocked and removed from the track. Theshuttle (1626) and the portion of the snare loop assembly (1624)remaining outside of the elongate body (1620) may then be partially orfully retracted into the tip (1622) and the elongate body (1620).

In the illustrative variation of FIG. 16E, the shuttle (1626) may bereleased from the elongate body (1620) by removing the suture control(1634) from the handle (1628) and inserting a portion of the suturecontrol (1634) into an opening in the handle in order to engage theinserted portion of the suture control (1634) with a release assembly(not shown) provided within the handle (1628). For example, as thesuture control (1634) engages with or otherwise moves the releaseassembly, a lock wire coupling the shuttle (1626) to the tip (1622) mayretract, which may release the shuttle (1626) from the tip (1622) of theelongate body (1620). The engagement of the suture control (1634) withthe release assembly may, in some variations, further simultaneouslyrelease/unlock the lock (1632) or a limiter. Removal of the lock (1632)or disengagement of a limiter may allow the snare control (1630) to moveproximally further along a track of the handle (1628). Movement of thesnare control (1630) proximally to an end of the track may retract thesnare loop (e.g., the portion of the snare and retention member thatremain outside of the elongate body) and the shuttle into the lumen.

Next, FIGS. 16F and 16G illustrate retraction (1610) of the shuttle(1626) into the elongate body (1620) such as into a lumen (1636) of thetip (1622) and/or a corresponding lumen in the elongate body (1620). Forexample, in variations comprising a tip (1622), retraction of theshuttle (1626) may result in a portion of the snare loop becomingpositioned within a lumen of the elongate body and a portion of thesnare loop becoming positioned within a lumen of the tip (1622), or mayresult in the entirety of the snare loop becoming positioned within alumen of the elongate body (1620). It should be appreciated that afterthe shuttle is released, the snare loop may no longer have a loopconfiguration. After retraction, the shuttle may be positioned within alumen of the tip (1622), within a lumen of the elongate body (1620),partially within the lumens of both the tip (1622) and the elongate body(1620), or partially within the lumen of the tip (1622) and partiallyextending from a distal end of the device. In variations in which a tipis not used, retraction of the shuttle (1626) may result in the snareloop and the shuttle becoming positioned within a lumen of the elongatebody. Retraction of the snare loop assembly (1624) and the shuttle(1626) into the tip (1622) and/or elongate body (1620) may be controlledby sliding the snare control (1630) along an end portion (secondportion) of the track previously covered by the lock (1632) orpreviously blocked by the limiter. FIG. 16G shows the snare control(1630) at the end portion of the track (e.g., at a proximal end of thetrack) to fully retract the shuttle (1626) and snare loop assembly(1624) into the elongate body (1620) and tip (1622), and FIG. 16Fdepicts the snare loop and the shuttle fully retracted into the lumen(1636) of the tip (1622) and/or a corresponding lumen in the elongatebody (1620).

Once the shuttle and snare are retracted into the elongate body, thesuture loop may be tightened, or further tightened, around the targettissue (1612) using, for example, any of the tensioning devicesdescribed in U.S. patent application Ser. No. 13/490,919, entitled“Tissue Ligation Devices and Tensioning Devices Therefor” and filed onJun. 7, 2012, the contents of which are incorporated by reference hereinin their entirety. Finally, the closure device may be withdrawn from thebody (1614). As illustrated in FIGS. 16A-16G, the snare loop assembly(1624) and the shuttle (1626) may not be retracted until the shuttle(1626) is released from the tip (1622). In this manner, prematureretraction is prevented, thereby improving operability and safety of theclosure device.

FIG. 17A is a flowchart (1700) for another variation of a tissue closingprocess. FIGS. 17B-17G are perspective views of a snare loop assemblyand a handle corresponding to the various steps in FIG. 17A. Theflowchart (1700) begins with advancement of a closure device towardstarget tissue (1702). Once advanced to a desired position, a snare loopassembly may be closed around the target tissue (1704).

FIG. 17B illustrates an elongate body (1720) comprising a tip (1722),and a snare loop assembly (1724) comprising a shuttle (1726) positionedwithin a shuttle recess of the tip (1722). The snare loop assembly(1724) is illustrated in the open position, and may be modified by useroperation of the handle (1728) shown in FIG. 17C. In this configuration,the snare control (1730) may slide along the track, but is preventedfrom initiating a retraction operation of the snare loop assembly (1724)and shuttle (1726) by a lock (1732). A limiter as described with respectto FIGS. 14A-14B and 15A-15B may alternatively be coupled to the snarecontrol (1730) to prevent premature retraction of the snare loopassembly. The snare loop assembly (1724) may be opened and closed asnecessary to ensure that the target tissue is properly ligated. Thehandle (1728) may further comprise a suture control (1734) fortightening a suture loop.

After the snare loop assembly (1724) is determined to be positionedproperly, the suture loop may be released (1706) from the snare loopassembly (1724). A user may pull the suture control (1734) out from abase of a handle (1728) in order to release the suture loop from thesnare loop assembly (1724). The closed snare loop assembly (1724) maythen be opened (1708), as shown in FIG. 17B. After opening the snareloop assembly (1708), the suture loop may be tightened (1710) around thetarget tissue. Then, the shuttle (1726) may be released (1712) from theelongate body (1720), as illustrated in FIGS. 17D and 17E. The releaseof the shuttle (1726) from the shuttle recess of the tip (1722) is shownin FIG. 17D and allows retraction of the snare loop assembly (1724) andthe shuttle (1726) into the tip (1722) and the elongate body (1720).

In the illustrative variation of FIG. 17E, the shuttle (1726) may bereleased from the elongate body (1720) by removing the suture control(1734) from the handle (1728) and inserting the suture control (1734)into an opening in the handle to contact a release assembly (not shown)provided within the handle (1728). For example, the suture control(1734) may engage with the release assembly, which may retract a lockwire to release the shuttle (1726) from the elongate body (1720), asdescribed above. The engagement of the suture control (1734) with therelease assembly may, in some variations, further simultaneouslyrelease/unlock the lock (1732). The lock (1632) may then be removed fromthe track to allow the snare control (1730) to be moved furtherproximally along the track of the handle (1728).

Next, FIGS. 17F and 17G illustrate retraction (1714) of the shuttle(1726) into the elongate body (1720) such as into a lumen (1736) of thetip (1722) and a corresponding lumen in the elongate body (1720). Thesnare loop assembly (1724) and the shuttle may be retracted (1714) intothe tip (1722) and the elongate body (1720) by sliding or otherwisemoving the snare control (1730) proximally along an end portion (secondportion) of the track previously covered by the lock (1732). FIG. 17Gshows the snare control (1730) at the end portion (e.g., a proximal end)of the track to fully retract the shuttle (1726) and snare loop assembly(1724) into the elongate body (1720).

Finally, the closure device may be withdrawn from the body (1716). Asillustrated in FIGS. 17A-17G, the snare loop assembly (1724) and theshuttle (1726) may not be retracted until the shuttle (1726) is releasedfrom the tip (1722). In this manner, premature retraction may beprevented, thereby improving operability and safety of the closuredevice.

III. Systems

Described here are systems for closing tissue, for example, a leftatrial appendage. In general, the systems may comprise any of theclosure devices described herein, together with one or more additionalcomponents. For example, the system may comprise a guide devicecomprising a lumen therethrough. The lumen may be sized and configuredto receive an elongate body of a closure device described here. In someembodiments, the system may comprise a first guide wire having a sizeand length adapted for accessing the left atrial appendage through thevasculature and comprising an alignment member, a second guide wirehaving a size and a length adapted for accessing the pericardial spacefrom a subthoracic region and comprising an alignment member, and aclosure device. The alignment member may be any suitable alignmentmember. For example, the alignment member may comprise radiopaque orechogenic markers, members configured to produce an audible response,one or more interconnecting members, one or more vacuum members, ormagnets. The systems may further comprise instructions for use.

Although the foregoing implementations has, for the purposes of clarityand understanding, been described in some detail by of illustration andexample, it will be apparent that certain changes and modifications maybe practiced, and are intended to fall within the scope of the appendedclaims. Additionally, it should be understood that the components andcharacteristics of the devices described herein may be used in anycombination. The description of certain elements or characteristics withrespect to a specific figure are not intended to be limiting or norshould they be interpreted to suggest that the element cannot be used incombination with any of the other described elements.

We claim:
 1. A device for closing a target tissue comprising: anelongate body comprising a lumen therethrough, wherein the elongate bodycomprises a tip at a distal end, wherein the tip comprises a first lumenand a side opening, wherein the first lumen extends through the elongatebody, wherein the side opening extends along a side wall of the elongatebody; a snare loop assembly comprising a snare and a suture loopreleasably coupled to the snare, the snare loop assembly extending fromthe tip, wherein the snare comprises a moveable proximal end and adistal end releasably coupled to the elongate body, wherein the moveableproximal end of the snare extends from the first lumen, wherein thedistal end of the snare extends from the side opening; and a handleconfigured to retract the distal end of the snare into a lumen of theelongate body after the distal end is released.
 2. The device of claim1, wherein the tip comprises a second lumen, wherein the second lumenextends through the elongate body.
 3. The device of claim 2, wherein thesuture loop comprises a suture knot, wherein the suture knot extendsthrough the second lumen.
 4. The device of claim 1, further comprising ashuttle at the tip and coupled to the distal end of the snare, whereinthe shuttle releasably couples the distal end of the snare to theelongate body.
 5. The device of claim 4, wherein the distal end of thesnare is positioned in the side opening when the shuttle is coupled tothe elongate body.
 6. The device of claim 4, wherein the shuttle fixedlycouples the distal end of the snare to the elongate body in a deployedconfiguration.
 7. The device of claim 6, wherein the shuttle is coupledto a side wall of the elongate body in the deployed configuration. 8.The device of claim 4, wherein the shuttle has a maximum dimension thatis less than a diameter of the lumen.
 9. The device of claim 1, whereinthe side opening is an L-shaped recess in a side wall of the elongatebody.
 10. The device of claim 1, wherein a distal portion of the snareis positioned in the side opening when the distal end of the snare iscoupled to the elongate body.
 11. The device of claim 1, wherein thehandle comprises a track, a snare control coupled to the track, and alock configured to limit movement of the snare control along the track,wherein the lock is releasably coupled to the track.
 12. The device ofclaim 11, wherein the handle further comprises a release assemblyconfigured to release the distal end of the snare from the elongate bodyand allow movement of the snare control along the track.
 13. The deviceof claim 12, wherein the track comprises a first portion and a secondportion, and the lock limits movement of the snare control along thesecond portion of the track.
 14. The device of claim 1, wherein aproximal portion of the tip comprises a tip chamfer.
 15. The device ofclaim 14, wherein the tip chamfer is 30 degrees and offset from the tiplumen.